Fluid operated pump with removable engine valve



Oct. 19, 1965 c. .1. coBERLY 3,212,445

FLUID OPERATED PUMP WITH REMOVABLE ENGINE VALVE CLARENCE d. 605520/ 5) H/S A77OQA/E'Y5 HABE/5, MECH, RUSSELL, Kee/v Oct. 19, 1965 c..1. coBERLY FLUID OPERATED PUMP WITH REMOVABLE ENGINE VALVE Filed July l, 1965 6 Sheets-Sheet 2 Pz 6.4.

INVENTOR.

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Filed July 1, 1963 C. J. COBERLY FLUID OPERATED PUMP WITH REMOVABLE ENGINE VALVE 6 Sheets-Sheet 3 I M44@ Wj@ YLn/00 cww A /94 46/ INVENTOR.

CLARENCE J. COBERLY 5y H/s Arme/ways HAee/s, MECH, RUSSELL /fseA/ Oct. 19, 1965 c. J. coBERLY 3,212,445

FLUID OPERATED PUMP WITH REMOVABLE ENGINE VALVE m HAee/s, 4f/5CH, Rass/:11. KERN Oct. 19, 1965 c. J. coBERLY 3,212,445

FLUID OPERATED PUMP WITH REMOVABLE ENGINE VALVE INVENTOR.

. @AREA/c5 J CUBE/21M BY /6//5 ATTfe/UEVS #AeB/5, /v//Ec/f, Russ/51.1, Kee/u Oct. 19, 1965 c. J. coBERLY 3,212,445

FLUID OPERATED PUMP WITH REMOVABLE ENGINE VALVE Filed July l, 1965 6 Sheets-Sheet 6 IN VEN TOR.

CLA 25A/c5 d. 6055,@ y

BY //S ATTORNEYS HA/a/e/s, /f/Ecff, Russe/.L KERN United States Patent 3,212,445 FLUID OPERATED PUMP WITH REMOVABLE ENGINE VALVE Clarence J. Coberly, San Marino, Calif., assignor to Kobe, Inc., Huntington Park, Calif., a corporation of California Filed July 1, 1963, Ser. No. 291,810 14 Claims. (Cl. 10S-46) The present invention relates in general to fluid operated pumps for wells, especially oil wells, and, more particularly, to a uid operated pump or pump assembly which includes separate pump and engine valve units.

Fluid operated pump assemblies comprising separate pump and engine valve units are disclosed in my Patent No. 2,949,857, issued August 23, 1960, and in Patent No. 3,034,442, issued May 15, 1962 to Val Kogut and me. In both of these patents the valve units are spaced from the pump units in operation, and are installable in and removable from the well independently of the pump units, preferably by circulating them in and out hydraulically. In Patent No. 2,949,857, the pump and valve units are located in side-by-side relation in operation, and the pump unit is also hydraulically installable and removable. In Patent No. 3,034,442, the fluid operated pump unit is of the fixed type, only the valve unit being hydraulically installable and removable.

Since the engine valve of a fluid operated pump is the component thereof which most frequently requires repair or replacement, an important advantage of the fluid operated pumping system disclosed in each of the aforementioned patents resides in the fact that the valve unit can be repaired -or replaced without taking the pump unit out of service. Additionally, such a separate valve unit is relatively small and thus has the advantage of enabling a pumper to carry enough of them in an automobile to service a large number of wells, there being no necessity for utilizing a large service truck capable of transporting a considerable quantity of complete fluid operated pumps. Also, -since engine valves for fluid operated pumps are precision devices which can be repaired properly only by skilled mechanics in shops provided with precision equipment, separate engine valve units, being small and light, may be flown great distances to a properly equipped shop at small cost. Thus, by utilizing separate valve units, one shop can service all of the valve units from every oil field in an extremely large area without excessive delay and at a lower net cost than would be the case if it were necessary to service the entire fluid operated pump.

The basic object of the present invention is to provide a fluid operated pump assembly which takes advantage of the foregoing features of a Separate engine valve unit in an apparatus wherein the valve unit is carried by the pump unit.

More particularly, a primary object of the invention is to provide a fluid operated pump assembly, comprising separate pump and engine valve units, wherein the valve unit is removably disposed in a valve-unit chamber in the pump unit. Thus, the separate engine valve unit can readily be removed from the pump unit for service or repair, being immediately replaced by a similar valve unit so that the pump unit may be put back in operation immediately.

' Preferably, the fluid operated pump unit is of the type which is circulated into and out of the well hydraulically through a pump tubing set in the well. With this construction, the pump unit can be circulated out, the valve unit removed and replaced, and the pump unit circulated back in, all with a minimum of down time, this being an important feature of the invention.

` A further object in the foregoing connection is to proice vide a fluid operated pumping system wherein the pump tubing, through which the pump unit is circulated in and out, is an operating fluid supply tubing which is the inner tubing of a concentric tubing system, the outer tubing being a production tubing which conveys the spent operating fluid and the production fluid from the Well to the surface. Thus, the present invention permits taking advantage of a separate engine valve unit in a concentric tubing system of the so-called open type, wherein the spent operating fluid and the production fluid are conveyed to the surface in a single tubing. It will be understood, however, that the present invention may be utilized in other types of tubing systems.

An important object of the invention is to provide a fluid operated pump assembly, comprising a separate engine valve unit carried by the fluid operated pump unit, wherein the operating chamber for the valve unit is located in the engine piston of the pump unit.

Locating the operating chamber for the separate engine valve unit within the engine piston is advantageous because it minimizes the lengths of the various passages or ports needed to interconnect the engine means of the fluid operated pump unit and the engine valve means of the fluid operated valve unit to enable them to operate as required. In this connection, an object is to provide control ports or port means in the engine cylinder and piston for controlling the operation of the engine valve means in the removable valve unit contained in the engine piston Another object in this connection is to provide passages or passage means in the engine piston for conveying operating fluid under pressure to and spent operating fluid from the cylinder or cylinder means in which the engine piston reciprocates.

It will be apparent from the foregoing that the present invention locates all of the various ports and passages required for operation of the engine means of the pump unit and the engine valve means of the valve unit in the body of the valve unit, the engine piston and the engine cylinder. This provides a very compact construction, which is an important feature.

Another object of the invention is to discharge spent operating fluid from the engine means of the pump unit, and production fluid from the pump means thereof, into a tubular rod which interconnects the engine piston and the pump piston, the mixture of spent operating fluid and production fluid flowing from the tubular middle rod into the production tubing to be conveyed to the surface thereby.

An object related to the foregoing is to provide means for discharging the production fluid and the spent operating fluid into the production tubing at the lower end thereof so as to constantly flush away any sand tending to accumulate in the annulus between the production tubing and the housing for the pump unit at the lower end of the supply tubing.

Still another object is to provide sources of clean fluid for lubricating the pump piston and the middle rod seals in such a way that any leakage is in the form of clean fluid into dirty fluid so as to minimize wear. Another object in this connection is to provide means for conveying clean fluid to the pump plunger to lubricate same, comprising a passage which communicates with the interior of the tubular middle r-od adjacent the point at which spent operating fluid from the engine means is discharged thereinto. Thus, even though the spent operating fluid and the production fluid are both discharged into the tubular middle rod, only the spent operating fluid, which is clean fluid, is used to lubricatethe pump piston.

Other objects are to provide a fluid operated pump unit which includes a differential double-acting engine means connected to a differential double-acting pump means, and, wherein the engine valve unit for controlling this engine means is a three-way unit fully interchangeable with the engine valve units of the aforementioned patents.

The foregoing objects, advantages, features and results of the present invention, together with various other objects, advantages, features and results thereof which will be evident to those skilled in the fluid operated pump art in the light of this disclosure, may be achieved with the exemplary embodiment of the invention described in detail hereinafter and illustrated in the accompanying drawings, in which:

FIGS. l and 2 are semidiagrammatic views illustrating a fluid operating pumping system which embodies the invention and respectively illustrating two different sets of operating positions for various components of a fluid operated pump assembly of the invention;

FIG. 3 is a vertical sectional view of the upper end of an actual physical embodiment of a fluid operated pump assembly and pumping system of the invention;

FIG. 4 is a downward continuation of FIG. 3;

FIG. 5 is a downward continuation of FIG. 4;

FIG. 6 is a downward continuation of FIG. 5;

FIG. 7 is a downward continuation of FIG. 6;

FIG. 8 is a downward continuation of FIG. 7;

FIG. 9 is a downward continuation of FIG. 8;

FIG. 10 is a downward continuation of FIG. 9; and

FIG. 1l is a developed view of one surface of an engine piston of the invention, showing various ports and passages therein which cooperate with a separate engine valve unit removably contained in the engine piston.

General description Initially, the invention will be considered herein in connection with the semidiagrammatic views of FIGS. 1 and 2. However, the description of this semidiagrammatic presentation will be equally applicable to the actual physical embodiment illustrated in FIGS. 3 to 1l of the drawings.

Referring to FIGS. 1 and 2, the numerals 20 and 22 respectively designate concentric inner and outer tubings which are suspended in a well bore, not shown, from a well head, not shown, in the usual manner. As will become appa-rent, the inner tubing serves as a supply tubing for conveying operating fluid under pressure downwardly in the well from the surface, while the outer tubing 22 serves to convey production fluid from the well, and spent operating fluid, upwardly to the surface. Thus, in the particular construction illustrated, the supply and production tubings 20 and 22 form a concentric tubing system of the so-called open type.

Connected to the lower end of the inner, supply tubing 20 is a tubular bottom hole housing 24 the lower end of which is seated on an annular seat 26 provided by a bottom shoe 28 to which the lower end of the production tubing 22 is connected. The bottom hole housing 24 is provided adjacent its lower end with an internal annular seat 30 for a standing valve assembly 32, which includes the usual standing valve 34. The standing valve assembly 32 is of generally conventional construction so that a detailed description is not necessary.

The standing valve assembly 32 is provided at its upper end with an annular seat 36 for the lower, inlet end of a fluid operated pump, or pump assembly, 40 capable of being hydraulically circulated into and out of the well through the supply tubing 20. In running the fluid operated pump 40 in, fluid under relatively low pressure is introduced into the supply tubing 20 thereabove. Fluid beneath the pump 40 is displaced into the production tubing 22, i.e., into the annulus between the supply and production tubings, by way of a passage means 42. The latter comprises ports 44 located above the annular seat 30 for the standing valve assembly 32 and formed in an inner tubular structure 46 of the bottom hole housing 24, an annulus 48 between the inner tubular structure 46 and an outer shell 50 of the bottom hole housing, and ports 52 formed in the outer shell 50 and communicating with the annulus between the supply and production tubings 20 and 22 adjacent the lower end of such annulus. In circulating the fluid operated pump 40 out of the well, the flow through the supply and production tubings 20 and 22 is reversed. In other words, fluid under pressure is introduced into the production tubing 22 at its upper end, and enters the interior ofthe inner tubular structure 46 of the bottom hole housing 24 below the fluid operated pump 40, by way of the hereinbefore-described passage means 42, to displace the pump upwardly out of the bottom hole housing and through the supply tubing 20 to the surface. Circulating a fluid operated pump in and out in this manner is generally conventional so that a more detailed description is not believed to be necessary.

Fluid operated pump unit 60 As hereinbefore outlined, the fluid operated pump or pump assembly 40 is divided `into two separate units, one being a fluid operated pump unit 60 and the other being a fluid operated engine valve unit 62 removably carried by and controlling the operation of the pump unit. The general structure and operation of the fluid operated pump unit 60 will now be considered, to be followed in a subsequent section of this specification by a description of the fluid operated engine valve unit 62 and its relationship to the pump unit.

The fluid operated pump unit 60 includes an elongated pump body 64 provided at its upper end with the usual packer mandrel 66. Within the pump body 64 adjacent its upper end is a fluid operated engine means 68 which actuates a pump means 70 located within the pump body adjacent its lower end. As will become apparent, both the engine means 68 and the pump means 70 are of the differential area, double acting type, the pump means being double acting in the sense that it draws in fluid from the Well during both strokes.

The fluid operated engine means 68 includes an engine piston or piston means 72 axially, i.e., vertically, reciprocable in an engine cylinder 74. The pump means l 78 includes a pump piston or piston means 76 axially reciprocable in a pump cylinder 78 and connected to the engine piston 72 by an axially extending, tubular middle rod 80.

As will be explained in more detail hereinafter, both the spent operating fluid discharged by the engine means 68 and the production fluid from the well discharged by the pump means 70 enter the tubular middle rod 80. The spent operating fluid and the production fluid flow from the interior of the tubular middle Irod 80, through ports 82 therein, into an annulus 84 between the rod 80 and the pump body 64. The annulus 84 lies between the engine and pump cylinders 74 and 78 and is of sufllcient axial length that the p-orts 82 are in constant communication therewith. From the annulus 84, the spent operating fluid and the production fluid flow through registering ports 86 and 88 into the upper end of the annulus 48 between the inner tubular structure 46 of the bottom hole housing 24 and the outer shell 50 thereof. The ports 86 are formed in the pump body 64 and the ports S8 are formed in the inner tubular structure 46 of the bottom hole housing 24. It will be noted that the spent operating fluid and production fluid flow downwardly through the annulus 48 substantially to the lower end of the annulus between the supply tubing 20 and the production tubing 22, before escaping into the latter annulus by way of the passage means 42. This bottom discharge for the spent operating fluid and production fluid mixture minimizes any tendency for sand to accumulate in the annulus between the supply and pro duc-tion tubings 20 and 22.

Turning now to a more detailed consideration of the engine means 68, the lower end of the engine piston :72 is constantly exposed to the operating fluid pressure 1n the supply 4tubing 20 through a passage means 90 which includes radial ports 92 in the packer mandrel 66 adjacent its upper end, an axial passage 94 in the packer mandrel bypassing the usual packers thereon, radial ports 96 in the packer mandrel connecting the lower end of the axial passage 94 to an annulus 98 between the supply tubing 20 and the pump body 64 externally of the engine cylinder 74, radial ports 100 in the pump body 64 below the engine cylinder, and an annulus 102 encompassing the tubular middle rod 80 and communicating at its upper end with the lower end of the engine cylinder 74, the lower end of the annulus 102 being closed by a sealing assembly 104 carried by the pump body 64 and engaging the tubular middle rod. It will be noted that reversed flow through the passage means 90 is prevented by an upwardly-spring-biased check valve 106 located in the packer mandrel 66 and engageable with an annular seat at the lower end of the axial passage 94 in the packer mandrel. When the fluid operated pump assembly 40 is being circulated out hydraulically, the check valve 106 seats to prevent bypassing of the packers on the packer mandrel.

As explained above, the passage means 90 constantly applies the operating fluid pressure in the supply tubing 20 to the lower end of the engine piston 72. The area at the lower end of the engine piston 72 on which the operating fluid pressure acts constantly is an annular one equal to the difference between the area of the engine cylinder 74 and the external area of the tubular middle rod 80. As will be discussed hereinafter in considering the fluid operated engine valve unit 62 in detail, this valve unit is adapted to apply an alternating fluid pressure to the upper end of the engine piston 72. The fluid pressure applied to the upper end of the engine piston is either the operating fluid pressure in the supply tubing 20, or the pressure of the mixture of spent operating fluid and production fluid in the production tubing 22. These alternately applied fluid pressures act on the entire area of the engine piston 72. Consequently, when the pressure of the production and spent operating fluid column acts on the upper end of the engine piston 72, lthe operating fluid pressure applied to the lower end of the engine piston produces the upward stroke of the engine and pump pistons 72 and 76. This condition is shown in FIG. 1 of the drawings. Conversely, when 'the operating fluid pressure in the supply tubing 20 is applied to the upper end of the engine piston 72, the downward stroke of the engine and pump pistons 72 and 76 occurs. This condition is illustrated in FIG. 2 of the drawings. It will thus be noted that the fluid 4operated engine or engine means 68 is of the differential area, double acting type. The area of the rod 80 is normally made one half of the area of the piston 72, thus balancing the operating fluid usage on the up stroke and the down stroke and balancing the Work done on the two strokes. This engine is therefore a balanced differential area double acting type.

`Considering now the pump means 70, the pump cylinder 78 is sealed at its upper end by a `sealing assembly 110 which engages the tubular middle rod 80 at the lower end of the production and spent 4operating fluid annulus 84 around the rod. Thus, the upper and lower ends of the annulus 84 are defined by the sealing assemblies 104 and 110, respectively. It should be noted that the diameters of the seals 104 and 110 are equal as shown, but these diameters could be unequal, as noted above the rod 80 and the seal diameter 104 are selected to give a lrod area equal to -one half the piston area 72. The seal diameter 110 is selected to give a pump rod area equal to one half the .area of the pump piston 76, making the pump differential and double acting, and balanced the same as the engi-ne. Since the example shown has these two seals equal, the pump piston 76 is equal in diameter to the engine piston 72 and therefore the area ratio of the engine to pump is 1:1.

The lower end of the pump :cylinder 78 communicates, through a standing valve 112, with an axial inlet 114 for well fluid, this axial inlet communicating with the .well through the standing valve assembly 32. The pump piston 76 is provided therethrough with a longitudinal passage means, controlled by a working valve 116, which communicates at its lower end with the lower end of the pump cylinder 78, and which communicates at its upper end with the interior of the tubular middle r-od 80.

As shown in FIG. Il of the drawings, during the upward stroke of the engine and pump pistons 72 and 76, the working valve 116 is closed and the standing valves 112 and 34 are open. Thus, fluid from the Well is drawn into the lower end of the pump .cylinder 78 from the well through the standing valve assembly 32 and the standing valve 112. Additionally, yfluid lfrom the upper end of the pump cylinder 78 is displaced into the lower end of the pump cylinder 4by way of a passage means 120 and the axial inlet 114. This passage means 120 includ-es radial ports 122 in the pump body .at the upper end of the pump cylinder 78, an annulus 124 between the pump body and the inner tubular structu-re 46 of the bottom hole housing 24, and at least one radial port 126 leading to the axial inlet 114.

Referring to FIG. 2 of the drawings, during the downward stroke of the engine and pump pistons 72 and 76, the working valve 116 is open, the standing valve '112 is closed, and the standing valve 34 is open. Fluid in the pump cylinder 78 below the pump piston 76 is thus displaced upwardly into the tubular middle Irod 80, and thence through the ports 82, the annulus 84 and the ports 86 and 88 into the production and spent operating fluid annulus between the supply and production tubings 20 and 22. At the same time, additional well fluid is drawn upwardly through the standing valve assembly 32, the axial inlet 114, and the passage means 120, into the upper end of the pump cylinder 78.

It will thus be apparent from the explanation given above that the pump means 70 is double acting insofar as its dis-charge is concerned, and it is also double acting insofar as its intake is concerned. In other words, the pump 70 draws fluid from the well during both strokes of the engine and pump pistons 72 and 76.

The foregoing completes a description of the structure and operation -o'f the fluid operated pump unit 60. The structure and operation of the fluid operated engine valve unit 62, and the manner in which this valve unit controls the engine 68, will be considered in the next section of this specification.

Fluid operated engine valve unit 62 The fluid operated engine valve unit 62 is substantially identical to that illustrated in FIGS. 5, 6 and l5 to 32 of my Patent No. 2,949,857, and described in the corresponding portion of the specification thereof. The overall relationship of the engine valve unit 62 to the fluid operated pump unit 60 is also quite similar. Consequently, a complete description herein is unnecessary, it being necessary only to -consider the location of the engine valve unit 62 in accordance with the present invention, and the general manner in which it controls the pump unit 60.

In accordance with the present invention, the engine piston 72 is provided therein with an axial valve-unit lchamber 130 in which the separate engine valve unit 62 is removably seated and releasably retained. The engine valve unit 62 may be removably seated in and releasably retained in the valve-unit chamber 130 in the engine piston 72 in any suitable manner. As shown in FIG. 5 of the drawings, the engine piston 72 provides an annular seat 132 for the lower end of the engine valve unit 62, an annular seal 134 being interposed 'between this annular seat and the valve unit. For proper circumferential indexing of the engine valve unit 62, it is provided at its lower end with .an axial extension 136 of square, or other noncircular, cross section disposed in a complementary socket 138 in the engine piston. As shown in FIG. 4, the engine valve unit 62 may be releasably retained in its chamber 1.30 by an internally-wrenchable nut 140 threaded into the upper end of the engine piston 72.

Preferably, the packer mandrel 66 is threadedly connected to the upper end of the engine cylinder 74, as shown at the upper end of FIG. 4 of the drawings. Thus, removal of the engine valve unit 62 from its chamber 130 in the engine piston 72 simply involves unscrewing the packer mandrel 66 from the upper end of the engine cylinder 74, -disengaging the nut 141), or other retainer means, 'from the upper en-d of the engine piston 72, vand withdrawing the engine valve unit 62 from its chamber 130. A replacement engine valve unit can then be inserted into the chamber 134) and the pump unit 60 reassembled.

The foregoing operations of removing `and replacing the engine valve unit 62 can be performed very quickly in the field, thereby minimizing the length of time the fluid operated pump 4) is out of service. The engine valve unit 62 which is removed can then be serviced or repaired, at any suitable location, without any necessity for taking the entire lluid operated pump 46 out of service. As previously pointed out, since the engine valve unit 62 is quite small, a pumper can carry enough engine valve units 62 for servicing a large number of wells in an ordinary passenger automobile, thereby avoiding any necessity f-or utilizing a large service truck.

Turing now to a consideration of the manner in which the engine valve unit 62 controls the uid operated engine 68, the engine valve unit includes a valve body 142 -containing an axially, i.e., vertically, reciprocable valve member 144 provided therein adjacent its lower end with an external annular channel 146. -(As hereinbefore pointed out, the engine valve unit 62 is substantially identical to that illustrated in FIGS, 5, 6 and l5 t-o 32 of my Patent No. 2,949,857, but it is inverted in position.) The valve member 144 is reciprocable between lower and upper positions, being shown in its lower position in FIG. l and in its upper position in FIG. 2.

When the valve member 144 is in its lower position, the external annular channel 146 therein applies the pressure of the spent operating fluid in the tubular middle rod 8) to the upper end of the engine piston 72, thereby producing the upward stroke of the engine and pump pistons 72 and 76. More particularly, when the valve member 144 is in its lower position, the annular channel 146 cornmunicates with a passage means 148 leading from the tubular middle rod 80, and communicates with a passage means 150 leading to the upper end of the engine cylinder 74. The passage means 148 and 15) are formed in the engine piston 72 and will be considered in more detail hereinafter.

Conversely, when the valve member 144 is in its upper position, as shown in FIG. 2 of the drawings, it moves above the lower end of the passage means 150 to permit communication between .this passage means and a passage means 152 leading from the lower end of the engine cylinder 74 to the interior of the valve body 142. Under these conditions, the operating uid pressure constantly present in the lower end of the engine cylinder 74 is communicated to the upper end of the engine piston 72, by way of the passage means 152 and 150, to produce the downward stroke 'of the engine and pump pistons 72 and 76.

As the engine piston 72 reaches the upper end of its stroke, the valve member 144 is hydraulically shifted upwardly into its uppel position to reverse the direction of motion of the engine piston, and, as the engine piston reaches the lower end of its stroke, the valve member 144 is hydraulically shifted downwardly into its lower position to once again reverse the direction of motion of the engine piston, all as fully described in my Patent No. 2,949,857. Therefore, a complete description herein is unnecessary.

Briefly, as the engine piston 72 approaches the end of its upward stroke, an annular control port or channel 154 in the engine cylinder 74, adjacent the upper end of the engine cylinder, bridges suitable control port or passage means in the engine piston 72 to cause upward shifting of the valve member 144 into `its upper position. Similarly, as the engine piston 72 approaches the end of its downward stroke, an annular control port or channel 156 in the engine cylinder 74, adjacent the lower end of the engine cylinder, bridges control port or passage means in the engine piston for shifting the valve member 144 into its lower position. The port or passage means which are bridged yby the upper control channel 154 to shift the valve member 144 upwardly, when the engine piston 72 reaches the end of its upward stroke, are designated generally in FIGS. 4 and 5 by the reference numerals 158 and 160, respectively. The port or passage means which are bridged by the lower control channel 156 to shift the valve member 144 downwardly, when the engine piston 72 reaches the end of its downward stroke, are designated generally in FIG. 5 by the reference numerals 162 and 164, respectively.

As previously pointed out, the manner in which the control passage means 158 and 160 cooperate with the control channel 154 to shift the valve member 144 upwardly, and the manner in which the control passage means 162 and 164 cooperate with the control channel 156 to shift the valve member 144 downwardly, `are fully disclosed in my aforementioned Patent No. 2,949,857. Consequently, a detailed description of the operation of the engine valve unit 62 herein is unnecessary. However, the structures of the various passage means 148, 150, 152, 15S, 160, 162 and 164 will now be considered.

Passage means in engine piston 72 Referring to FIGS. 4 andv 5 of the drawings, it will be noted that the engine piston 72 comprises an engine piston body 166 having an outer sleeve 168 telescoped thereover with a press lit. Various ones of the hereinbefore-mentioned passage means are formed by longitudinal grooves which are milled in the external surface of the engine piston body 166 and which are closed by the sleeve 168.

Turning to FIG. l1, which is a developed view of the external surface of the engine piston body 166, the passage rneans 148 includes longitudinal grooves 176 in the engine piston body 166. Similarly, the passage means and 152 respectively include longitudinal grooves 172 and 174 in the engine piston body 166.

Continuing to refer to FIG. 11, the control passage means 158 and 160 respectively include longitudinal grooves 176 and 178 in the external surface `of the engine piston body 166. The control passage means 158 and are also provided at their upper ends with radial ports extending outwardly through the outer sleeve 168, as suggested by broken lines in FIG. ll, and as shown in FIG. 4, such radial ports being bridgeable by the control channel 154. The control passage means 158 and 160 further include radial ports extending inwardly into communication with the engine valve unit 62 at their lower ends, as shown in FIG. 5.

The control passage means 162, as shown in FIGS. 5 and 11, merely comprises radial ports extending through the engine piston sleeve 168 and body 166 into communication with the engine valve unit 62. The control passage me-ans 164 merely comprises radial ports extending outwardly through the engine piston sleeve 166 and communicating at their inner ends with the longitudinal grooves forming the passage means 152. The outer ends of the radial ports forming the passage means 162 and 164 are bridgeable by the control channel 156.

In addition to the foregoing port or passage means 148, 150, 152, 158, 160, 162 and 164, various other port or passage means are formed in the engine piston 72 and perform various other functions associated with the operation of the engine valve unit 62. However, a detailed description is not necessary herein since the manner in which the engine valve unit 62 operates is fully disclosed in my aforementioned Patent No. 2,949,857.

9 Lubrication of middle rod seals and pump piston As previously stated, one feature of the present invention is that the sealing assemblies 104 and 110 engaging the tubular middle rod 80, and the pump piston 76, are lubricated by clean operating uid in such a way that any leakage always takes the form of leakage of clean operating fluid into the possibly dirty production tluid. This insures that wear is minimized.

Considering rst the manner in which the upper sealing assembly 104 around the tubular middle rod 80 is lubricated, it will be noted from FIGS. `and 6 of the drawings that the full operating iluid pressure in the annulus 102 acts on the upper end of the sealing assembly 104. Since the pressure of the spent operating tluid and production uid in the annulus 84 acts on the lower end of the se-aling assembly 104, any leakage is always clean operating fluid at high pressure from the annulus 102 into the annulus 84. Thus, lubrication of the sealing assembly 104 is achieved without any danger of excessive wear by contact with possibly dirty production fluid.

As shown in FIGS. 6 and 7 of the drawings, the lower end of the supply tubing 70 communicates with the upper end of a passage 190, formed in the inner tubular structure 46 of the bottom hole housing 24. The passage 190 extends downwardly, FIG. 7, to radial ports 192 communicating with the sealing assembly 110 at approximately its midpoint. At this point, the sealing assembly 110 incorporates Belleville springs which permit clean operating fluid under high pressure to enter the interior of the sealing assembly 110. Such clean operating fluid, under high pressure, can leak axially in both directions into either the production and spent operating fluid annulus 84, or the pump cylinder 78. Thus, again, any leakage is that of clean operating fluid into potentially dirty iiuid, thereby providing proper lubrication without any danger of Wear from contact with possibly dirty production uid.

Considering the manner in which the pump piston 76 is lubricated with clean fluid, the pump piston carries a tube 194 which extends axially upwardly into the tubular middle rod 80 to a point above the discharge ports 82 therein, as shown in FIGS. 6 and 7. Since the engine means 68 discharges clean, spent operating uid into the tubular middle rod 80 at the upper end thereof, the upper end of the tube 194 is exposed substantially only to clean, spent operating uid. Thus, such fluid can flow downwardly through the tube 194 into radial passages 196 leading to a piston ring groovedn the pump piston 76 at approximately the midpoint of the pump piston. Consequently, clean, spent operating iluid enters the interface between the pump piston 76 and the pump cylinder 78 to produce leakage of clean fluid into the potentially dirty production fluid in the pump cylinder. This minimizes wear of the pump piston 76 and the pump cylinder 78.

Although an exemplary embodiment of the invention has been disclosed herein for purposes of illustration, it will be understood that various changes, modifications and substitutions may be incorporated in such embodiment without departing from the spirit of the invention as defined by the claims which follow.

I claim:

1. A iiuid operated pump assembly, comprising a fluid operated pump unit including an engine piston having a valve-unit chamber therein and a self-contained, iluid operated valve unit for controlling the operation of said pump unit, said valve unit including a unitary valve body and valve means in said valve body for controlling the operation of said pump unit, said entire valve unit being removably positioned in said valve unit chamber.

2. In a fluid operated pump assembly, the combination of:

(a) a fluid operated pump unit including a pump body having therein fluid operated engine means including an engine piston having a valve-unit chamber therein and pump means operable by said engine means;

(b) a self-contained, iiuid operated engine valve unit;

and

(c) said entire valve unit being removably positioned in said valve-unit` chamber and provided therein with movable engine valve means for controlling the operation of said engine means.

3. In a fluid operated pump assembly, the combination (a) a fluid operated pump unit including a pump body having therein uid operated engine means having an engine piston with a valve-unit chamber therein and pump means operable by said engine means;

(b) a self-contained, uid operated engine valve unit;

(c) said valve unit being removably positioned in said valve-unit chamber and provided therein with movable engine valve means for controlling the operation of said engine means; and

(d) means removably retaining said valve unit in said valve-unit chamber.

4. In a fluid operated pump assembly, the combination (a) a fluid operated pump unit including a pump body having therein axially reciprocable, interconnected engine piston and pump piston means, said engine piston means having an axial valve-unit chamber therein;

(b) said engine and pump piston means being axially reciprocable in said pump body by an alternating tiuid pressure differential applied to said engine piston means;

(c) a self-contained, fluid operated engine valve unit;

and

(d) said valve unit including a unitary valve body axially removably positoned in said valve-unit chamber and provided therein with movable engine valve means for applying an alternating iluid pressure differential to said engine piston means so as to axially reciprocate said engine and pump piston means.

5. In a fluid operated pump assembly, the combination of:

(a) a iluid operated pump unit including a pump body having therein axially reciprocable, interconnected engine piston and pump piston means, said eng-ine piston means having an axial valve-unit chamber therein;

(b) said engine and pump piston means being axially reciprocable in said pump body by an alternating liuid pressure diiferential applied to said engine piston means;

(c) a self-contained, fluid operated engine valve unit;

(d) said valve unit including a unitary valve body axially removably positioned in said valve-unit chamber and provided therein with movable engine valve means for applying an alternating fluid pressure differential to said engine piston means so as to axially reciprocate said engine and pump piston means; and

(e) means removably retaining said valve body in said valve-unit chamber.

6. In a fluid operated pump assembly, the combination of:

(a) a fluid operated pump unit including a pump body providing axially oriented engine and pump cylinder means having therein axially reciprocable, interconnected engine piston and pump piston means, said engine piston means having an axial valve-unit chamber therein;

(b) said engine and pump piston means being axially reciprocable in said pump body by an alternating fluid pressure differential applied to said engine piston means;

(c) a self-contained, fluid operated engine valve unit;

(d) said valve unit including a unitary valve body axially removably positioned in said valve-unit chamber and provided therein with movable engine valve means for applying an alternating iiuid pressure differential to said engine piston means so as to axially reciprocate said engine and pump piston means; and (e) means removably retaining said valve body in said valve-unit chambe-r. 7. In a fluid operated pump assembly, the combination of:

(a) a fluid operated pump unit including a pump body providing axially oriented engine and pump cylinder means having therein axially reciprocable, interconmeans having therein axially reciprocable, interconnected engine piston and pump piston means, said nected engine piston and pump piston means, said engine piston means having an axial valve-unit chamengine piston means having an axial valve-unit chamber therein; ber therein; (b) said engine and pump piston means being axially (b) said engine and pump piston means being axially reciprocable in said pump body by an alternating reciprocable in said pump body by an alternating uid pressure differential applied to -said engine piston lluid pressure differential applied to said engine pis- 15 means; ton means; (c) a self-contained, fluid operated engine valve unit; (c) a self-contained, lluid operated engine valve unit; (d) said valve unit including a unitary valve body (d) said valve unit including a unitary valve body axially removably positioned in said valve-unit chamaxially removably positioned in said valve-unit chamber and provided therein with movable engine valve ber and provided therein with movable engine valve means for applying an alternating fluid pressure means for applying an alternating lluid pressure difdifferential to said engine piston means so as to ferential to said engine piston means so as to axially axially reciprocate said engine and pump piston reciprocate said engine and pump piston means; means; (e) means removably retaining said valve body in said (e) means removably retaining said valve body in valve-unit chamber; and said valve-unit chamber; and (f) control port means in said engine cylinder and (f) communicating port means in said engine piston piston means for controlling the operation of said means and said valve body. engine valve means. 1l. In a lluid operated pump assembly, the combination 8. In a lluid operated pump assembly, the combinaof; OII Ofi (a) a fluid yoperated pump unit including a pump body (a) a fluid operated pump unit including a pump body providing axially oriented engine and pump cylinproviding axially oriented engine and pump cylinder means having therein axially reciprocable, interconnected engine piston and pump piston means, said der means having therein axially reciprocable, interconnected engine piston and pump piston means, said engine piston means having an ax1al valve-unit engine piston means having an axial valve-unit chamber therein;

(b) said engine and pump piston means being axially reciprocable in said pump body by an alternating fluid pressure differential applied to said engine piston means;

(c) a self-contained, fluid operated eng-ine valve unit;

(d) said valve unit including a unitary valve body removably positioned in said valve-unit chamber and provided therein With movable engine valve means for applying an alternating fluid pressure differential chamber therein;

(b) said engine and pump piston means being axially reciprocable in said pump body by an alternating fluid pressure differential applied to said engine piston means;

(c) a self-contained, lluid operated engine valve unit;

(d) said valve unit including a unitary valve body axially removably positioned in said valve-unit chamber and provided therein with movable engine valve means for applying an alternating lluid pressure differential to said engine piston means so as to to said engine piston means so as to axially recip- 4U axially reciprocate said engine and pump piston rocate said engine and pump piston means; means;

(e) means removably retaining said valve body in said (e) means removably retaining said valve body in valve-unit chamber; said valve-unit chamber;

(f) control port means in said engine cylinder and (f) communicating port means in said engine piston piston means for controlling the operation of said engine valve means; and

(g) said control port means including axially spaced control ports in said engine cylinder means.

9. In a fluid operated pump assembly, the combination of:

(a) a iluid operated pump unit including a pump body providing axially oriented engine and pump cylinder means having therein axially reciprocable, interconnected engine piston and pump piston means, said engine piston means having an axial valve-unit chamber therein;

(b) said engine and pump piston means being axially reciprocable in said pump body by an alternating ilu-id pressure differential applied to said engine piston means;

(c) a self-contained, iluid operated engine valve unit;

(d) said valve unit including a unitary Valve body axially removably positioned in said valve-unit chamber and provided therein with movable engine valve '-0 means and said valve body; and

(g) interengageable indexing means on said engine piston means and said valve body for angularly orienting said valve body relative to said engine piston means to register said port means in said engine piston means and said valve body.

12. ln a lluid operated pump assembly, the combina-V tion of:

(a) a fluid loperated pump unit including a pump body providing axially oriented engine and pump cylinder means having therein axially reciprocable, interconnec-ted engine and pump piston means;

(b) said engine and pump piston means being axially reciprocable in saidpump body by an alternating fluid pressure differential applied to said engine piston means;

(c) a lluid operated engine valve unit carried by said pump unit;

(d) said valve unit including a valve body privided therein with movable -engine valve means for applymeans for applying an alternating fluid pressure differential to said engine piston means so as to axially reciprocate said engine and pump piston means;

valve-unit chamber; and

ing an alternating fluid pressure differential to said engine piston means so as to axially reciprocate said engine and pump piston means;

(e) a tubular axial rod interconnecting said engine and pump piston means;

12 wherein said lubricating means for said pump pis-ton means comprises a tube within said tubular rod.

(f) means for discharging spent operating uid from said engine cylinder means into said tubular rod;

(g) means for discharging production uid from said pump cylinder means into said tubular rod; and

(h) lubricating means communicating with said tubular 5 rod adjacent said di-scharge means of subparagraph (f) for conveying spent operating uid to said pump piston means to lubricate same.

13. A fluid operated pump assembly according to claim 14. In a fluid operated pump assembly, the combination fluid pressure differential applied to said engine pis- 20 ton means;

(c) said engine piston means being provided with an axial valve-unit chamber therein;

(d) a self-contained, Huid operated engine valve unit separate from said pump unit; 25

(e) said valve unit including a unitary valve body axially removably positioned in said valve-unit chamber and provided therein with movable engine valve means for applying an alternating Huid pressure differential to said engine pist-on means so as to axially reciprocate said engine and pump piston means; (f) means removably retaining said valve body in said valve-unit chamber; (g) a tubular axial rod interconnecting said engine and pump piston means; (h) means for discharging spent operating lluid from said engine cylinder means into said tubular rod; (i) means for discharging production lluid from said pump cylinder means intro said tubular rod; and

(j) lubricating means communicating with said tubular rod adjacent said discharge means of subparapragh (h) for conveying spent operating fluid to said pump piston means to lubricate same.

References Cited by the Examiner UNITED STATES PATENTS 746,206 12/03 Viggers 91-225 2,631,541 3/53 Dempsey 103-46 2,679,806 6/54 Chenault 103-46 2,943,576 7/60 English l03`46 2,949,857 8/ 60 Coberly 103-46 2,950,704 8/ 60 Andrews 9l-225 X 2,983,227 5/61 English 103-46 3,034,442 5/ 62 Coberly et al. 103`4'6` LAURENCE V. EFNER, Primary Examiner.

ROBERT M. WALKER, Examiner. 

1. A FLUID OPERATED PUMP ASSEMBLY, COMPRISING A FLUID OPERATED PUMP UNIT INCLUDING AN ENGINE PISTON HAVING A VALVE-UNIT CHAMBER THEREIN AND A SELF-CONTAINED, FLUID OPERATED VALVE UNIT FOR CONTROLLING THE OPERATION OF SAID PUMP UNIT, SAID VALVE UNIT INCLUDING A UNITARY VALVE BODY AND VALVE MEANS IN SAID VALVE BODY FOR CONTROLLING THE OPERATION OF SAID PUMP UNIT, SAID ENTIRE VALVE UNIT BEING REMOVABLY POSITIONED IN SAID VALVE UNIT CHAMBER. 